<header>
  <nav>
    <div>
      <i class="iconfont icon-nav hand" (click)="toggleSide()"></i>
    </div>
    <div class="fr">
      <span>
          {{username}}
      </span>
      <button md-icon-button [mdMenuTriggerFor]="menu">
        <img src="{{langImg}}" alt="">
      </button>
      <md-menu #menu="mdMenu" >
        <button md-menu-item (click)="changeLang('zh')" class="langimg">
          <img src="../../../assets/img/zh.jpg" >
          <span>{{'chinese' | translate}}</span>
        </button>
        <button md-menu-item (click)="changeLang('en')" class="langimg">
          <img src="../../../assets/img/en.jpg" >
          <span>{{'english' | translate}}</span>
        </button>
      </md-menu>
    </div>
  </nav>
</header>
